Exactly Gwylan. It's hard to know how Sam Allardyce could have done a better job at places like Bolton where they punched above their weight for YEARS, or West Ham where he got them promoted immediately and then consistently kept them top half, all against the back ground of hostil home...
He's right and you're wrong. He really hasn't failed anywhere he's gone, unless you include Newcastle (and that one is highly debatable):
https://en.wikipedia.org/wiki/Sam_Allardyce